Real time predictive control of generating system using hybrid computer and a fast time adaptive model PublicDeposited

Descriptions

A system consisting of two d-c generators, one exiting the other,
is controlled with an EAI 690 hybrid computer in an on-line operation.
The hybrid computer works as a predictive controller with an on-off
actuating signal. A fast-time, second-order model is used to determine
the switching time, and a small linear region is used to avoid limit-cycling.
A predictive control system of this kind has a time optimal response
when the controlled system is linear, stationary and of second
order. Since none of these conditions are satisfied, the response is
only quasi-optimal.
To improve the system performance an adaptive second-order
model was used. A parameter estimator calculates the gain and the equivalent time constant of the system and feeds these values into the
model.
The response was recorded for sudden load changes and for
build-up from minimum output to normal voltage. In all cases the
predictive control technique worked well, but small transient oscillations
were unavoidable in the linear region. Three different secondorder
models with fixed parameters were used, but none of the resulting
responses were as good as when the model was adaptive.